Interface matrix for dental restoration

ABSTRACT

Dental restoration. A glass filament mesh matrix has inner and outer faces, the inner face being adapted to be bonded to a natural tooth. An outer face of proper color is adapted to receive the final buildup of composite. The process of applying dental surface restoration matrix to the face of an existing natural tooth, comprising the following steps: 
     a. Lubricating the surface of the natural tooth, 
     b. Applying a glass filament matrix to the natural tooth, the matrix being impregnated with curable material, 
     c. Curing the matrix, 
     d. Removing the matrix from the natural tooth, 
     e. Applying composite surface material of the proper color to the outer surface of the matrix, 
     f. Replacing the matrix on the natural tooth with a bonding agent, 
     g. Curing the matrix by either heat or light.

TECHNICAL FIELD

This invention relates to dental restoration and more particularly, tocosmetic bonding.

The object of the invention is to allow either the Dentist or LaboratoryTechnician to fabricate a more precise addition to a natural tooth by:

1. having a better control of color (shade match).

2. easier chairside or laboratory buildup and adjustment.

3. ability to impart a three dimensional effect in the finalrestoration.

4. less Dentist and Laboratory time spent in construction.

PRIOR ART AND BACKGROUND

The present state of the art consists of two processes:

1. Chairside bonding process, where the Dentist builds the desiredshape, color and size of an addition to a natural tooth using acomposite material. He does this by laminating layers of composite overthe surface of a prepared, etched natural tooth. The chairside method isboth difficult and time consuming and only when completed does theDentist or Patient realize the aesthetic value of the work done. Thisaddition to the natural tooth is permanently bonded from the verybeginning of the operation and cannot be removed for any simple additionor adjustment.

2. The Laboratory process, which is constructed as a finished productcompleted on casts of a natural tooth using either resins or porcelain.

In this invention, the Laboratory processed veneer has greater densityand strength and allows for the Dentist and Patient to evaluate theaesthetic value before bonding permanently.

PROBLEMS

A. Poor coloring of the natural tooth: The only way this problem can becorrected by either the Lab process or Dentist buildup is by increasingthe thickness of the buildup. This will result in an oversized, bulkyrestoration. The only alternative would be for the Dentist to removesome natural tooth structure allowing for more thickness, a moreaesthetic final product.

The Invention:

This invention consists of a thin shell called the matrix, which isopacified to completely mask the underlying color of the natural tooth.This shell matrix is approximately three tenths of a millimeter inthickness and is adapted uniformly to the surface of the natural tooth.The result is a uniform, natural looking finished product.

B. Poor bonding at the interface of the natural tooth:

The composites on the market are: Filled, lightly filled and unfilled.If one uses a highly filled or lightly filled composite, the fill in thecomposite will actually act as a repellent to a complete bond at theinterface of the natural tooth. If one trIes to compensate by usingcombinations of materials they would be applied in an uneven mannerfurther creating problems.

This invention, consisting of a thin shell, has two receiving surfaces,the buildup interface and the tooth interface. (FIGS. 1 and 2) Due toits design, each of the interfaces are coated with the proper materialsto accept either the cementing medium or the buildup medium. The lightlyfilled resins are best for bonding purposes while the heavy filledresins are best for the outer surface because of its abrasionresistance.

C. Predicatable thickness of the final product: Using the state of theart technique, this cannot be achieved until the finish of therestoration and only the eye can decide this finished state.

This invention easily compensates for this problem because the matrix isthree tenths of a m.m. (0.3 mm) thick and adding two tenths of a m.m. ofshading material over this results in a restoration exactly five tenthsof a m.m. ( 0.5 mm) of thickness in the final product.

D. Strength: The strength of the materials on the market are only whatthe strength of the composite materials possess. This invention utilizesan interlocked weave of glass filaments in the matrix, which adds to theoverall strength of the completed restoration.

OBJECTS OF THE INVENTION

The principal object of the invention is to provide new and improveddental restoration means and methods.

Another object of the invention is to provide new and improved cosmeticbonding for dental restoration.

Another object of the invention is to provide new and improved cosmeticbonding for dental restorations using interlocking glass filaments.

Another object of the invention is to provide new and improved dentalrestoration means comprising: an interlocking glass filament matrix,having inner and outer faces, the inner face being adapted for bondingto the natural tooth and an outer face with proper depth of coloradapted for receiving the final buildup of the veneer.

These and other objects of the invention will be apparent from thefollowing specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 show sectional views of an embodiment of the invention.

BEST MODE OF THE INVENTION

FIG. 1 shows a sectional view of a natural tooth 1, having an outerenamel surface 2. An interlocking glass filament mesh 3 is placed overthe outer surface 4, of the tooth. A composite surface layer 5, isplaced on the outer surface of the glass filament mesh 3. The glassfilament mesh, is bonded to the tooth surface with compatible bondingmaterial 4' and the outer surface of the glass filament mesh is bondedby bonding material 5' to the surface material 5, FIG. 2, which ischosen to have the proper color.

FIG. 2 shows the complete assembly.

In the manufacture of the "matrix", the filament glass mesh acts as amixing device, allowing the tooth surface bonding material to mix withthe buildup surface bonding material prior to its curing. After curing,the resulting shell, or matrix, becomes rigid and is 3/10 of a m.m. (0.3mm) in thickness. If both the outer surface material and the innersurface material are dissimilar, they will chemically combine in theuncured state thus allowing different materials on the market a newoutlet. Example: where methyl methacrolate bonds poorly to a Bis G.M.A.material when either is in the cured state, the interface matrix itselfmay be treated in its manufacture to receive a methyl methacrolatesurface on either side.

Compositions that are state of the art today are Bis G.M.A. resins. Withour interface, we can actually add a dissimilar material such as acrylic(methyl methacrolate) to either the tooth surface or the buildup surface(outer surface).

Then after curing, they are chemically combined. If each surface wascured separately, and then cured together, they would not chemicallycombine. Therefore, the final matrix would have two surfaces fordifferent purposes.

When the cured matrix is lined up to the tooth, but not bonded to thetooth, either the Dentist or Lab Technician can now build up a compositematerial on the buildup surface of the matrix, restoring the desiredanatomy and color. If the Dentist, building up chairside, decides toremove the veneer from the tooth for better application in hand, he maydo so due to the fact that the tooth surface of the matrix is not yetbonded to the tooth. When he has completed the desired anatomy, and hasdecided no further work has to be done, he can permanently bond theveneer to the natural tooth by using an autocure or light cure cementingmaterial compatible with the tooth surface interface of the matrix. TheLaboratory procedure is similar, except, working is done on casts.

Laboratory Process:

1. The matrix supplied either to the Laboratory or Dentist comprises aglass filament pad, saturated on both sides with the proper material ina pliable, uncured consistency, sealed from exposure to light in acapsule or between plastic coated sheets of paper. This pad, which ispre-shaped to the approximate size of the natural tooth, is adapted tothe tooth surface which has been lubricated to prevent bonding at thisstage, and then cured by light application or heat cured depending onselection.

After curing, the pad now being rigid, can accept the proper buildup ofcomposite on the bonding surface of the matrix. Due to the lubricatedtooth surface, the entire system may be removed from the tooth wherefurther work may be done more conveniently. Upon completion of thedesired anatomy, the facing is ready to be bonded to the natural tooth.This is done by cleaning the surface of the tooth with a de-greasingmedium, then etching the tooth enamely properly The tooth surfaceinterface of the veneer is also de-greased and lightly scored. Theproper cementing medium is applied and the facing is auto-cured inplace.

2. Laboratory Kit: This kit consists of all separate components thatwill allow the Laboratory to fabricate the matrix on casts, saving theDentist valuable chair time. The Laboratory may also complete thebuildup for the final veneer, sending the Dentist the completedrestoration. The Laboratory may also be supplied with a factory curedmatrix that has an approximate size and shape. The Lab then relines thismatrix to the cast thereby forming a precise fit.

It is claimed:
 1. The process of applying a dental surface restorationmatrix to the face of an existing natural tooth, comprising thefollowing steps; a. lubricating the surface of the natural tooth, b.forming a glass filament matrix having inner and outer surfaces on thenatural tooth, coating the matrix with a first curable material on theouter face and a second curable material on the inner face, c. curingthe matrix assembly, d. removing the matrix assembly from the naturaltooth, e. applying composite surface material of the proper color to thefirst material on the outer surface of the matrix, f. replacing thematrix assembly on the natural tooth with a bonding agent.
 2. Laboratoryprocess of making a dental surface restoration comprising the followingsteps: a. making a casting of the natural tooth, b. forming a glassfilament matrix on the outer surface of the tooth casting, coating thematrix with a first curable hardening material on one side and a secondcurable material on the other side, c. curing the matrix using eitherlight of heat, d. removing the matrix from the casting, e. applying tothe matrix an outer surface of composite material of proper color toform an assembly, f. returning the completed assembly to the Dentist forapplication to the patient.
 3. Dental restoration means comprising: aglass filament matrix, an inner face and an outer face of differentmaterials attached to the matrix, the inner face being adapted to bondto a natural tooth and the outer face being adapted to be bonded to alayer of composite material simulating a natural tooth.